xsetroot

The xsetroot program allows you to tailor the appearance of the background ("root") window on a workstation display running X. Normally, you experiment with xsetroot until you find a personalized look that you like, then put the xsetroot command that produces it into your X startup file. If no options are specified, or if -def is specified, the window is reset to its default state. The -def option can be specified along with other options and only the non-specified characteristics will be reset to the default state.

Only one of the background color/tiling changing options (-solid, -gray, -grey, -bitmap, and -mod) may be specified at a time.